Power Detection of Microwave Sensor With Wide Range via Near-Field Coupling

This study primarily offers a theoretical analysis and experimental validation of microwave power detection based on the variations in the probe signal of the scanning microwave microscopy and the microwave signal from the surface of electronic devices. On the one hand, maintaining constant input power for the sample and the probe, we analyze the shift in the peak-to-peak value of the
$S_{{11}}$
curve with power differences at surface positions. On the other hand, maintaining a constant test position and varying input power of the probe, the peak-to-peak measurement sensitivity varies nonlinearly with the surface microwave power. Based on the relevant theoretical and experimental results, it has been determined that modifying the input power of the probe has the potential to enhance the sensitivity of microwave power measurement and extend the range of power measurement. This article establishes the upper and lower power detection thresholds at 12 and −60 dBm, respectively. These results offer valuable insights for effectively detecting surface power levels of microwave electronic devices with wide-ranging capabilities and high sensitivity.